Infragistics Forums

 Hello,

How can I use UltraChart with logarithmic grid lines for X or Y axes? I'm not speaking of logarithmic scale for X or Y axis, but to draw the grid itself, like what's shown in http://en.wikipedia.org/wiki/Image:600px-LinLogScale.png

Regards

MG 

Sure, first you need to enable the minor gridlines: chart.Axis.X.MinorGridLines.Visible = true;
set the following properties under chart.Axis.X

NumericAxisType = Logarithmic
TickmarkStyle = DataInterval
TickmarkInterval = 1
RangeMin = 1
RangeMax = 1000
RangeType = Custom

It works  -thanks!

 How with a logarithmic scale can I display a value of zero for ultraChart1.Axis.X.RangeMin? If I set it to zero, it triggers an exception (as it if was computing log(zero) rather than simply displaying the value), but if I set it to 1, it displays 1 as the min value...

Am I missing something? 

Set LogZero property under chart.Axis.X. This property was added in 7.3. If you're using an earlier version, you'll have to start your range with 1.
http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/Win_Support_for_Zero_Data_Points_in_Charts_Having_Logarithmic_Axes_Whats_New_20073.html

 Thks again for your answer. Yes, I'm using 7.3. Yet, even if I set the LogZero property (before or after setting NumericAxisType = NumericAxisType.Logarithmic), I still get an exception

- either if I have a value of 0 in my datasource,

- or if I set ultraChart1.Axis.X.RangeMin = 0.

What do I do wrong?

I can't reproduce the first problem (having 0s in the datasource). Have you tried installing the latest hotfix?
Setting RangeMin to 0 on a logarithmic axis with RangeType=Custom will not work, unfortunately. LogZero was only designed to modify the zero values on the data. You can submit a feature request here, if you want this included in the future chart releases:
http://devcenter.infragistics.com/protected/requestfeature.aspx